The invention relates to a method and device for detecting a fire alarm system based on a linear flame sensor. The method for detecting the fire alarm system based on the linear flame sensor comprises the steps that the short circuit state and the open circuit state of the linear flame sensor are detected; if the short circuit state and/or the open circuit state exist/exists, the working performance parameter of the linear flame sensor is detected after the corresponding fault position is determined and a fault is removed; a data packet is sent to an acquisition and analysis module through simulation, and whether the short circuit state and the open circuit state of the linear flame sensor can be accurately judged by the acquisition and analysis module and whether the alarm function is normal or not are judged according to the analysis result on the data packet by the acquisition and analysis module. According to the method and device for detecting the fire alarm system based on the linear flame sensor, the fault and the performance of the fire alarm system can be detected rapidly and automatically.